Remote power substations, owned by the utility power companies, are monitored and managed via redundant Operations Control Centers (OCC), located in the coverage region of the utility power companies. Power distribution equipment installed at these remote power substations often provide built-in digitized monitoring subsystems that connect to the utility power company's secure supervisory control and data acquisition (SCADA) network to communicate critical data back to the OCCs. However, in some cases, either the original equipment manufacturers neglect to provide the built-in monitoring capability, for their power distribution equipment, at the remote sites or the equipment is so old that the digitized monitoring technology was not available at the time of equipment manufacture.
In either of those cases, the power distribution equipment's operational monitoring data can only be collected via manual reading of display dials physically mounted on the Original Equipment Manufacturer (OEM) equipment (in our specific case—the current position of a tap dial for a switchable power transformer), on location, at the remote power substations. This approach requires significant manpower resources, deployed in the field, to monitor and collect this critical operational data to be relayed back to the OCC.
Prior art addresses the problem of remotely reading a dial through the use of cameras and light sensors. These solutions are either physically large and/or bulky, which makes them unusable for small dials or tight spaces. The miniaturization of electronics over the past decade means these technologies could be made to work in smaller spaces, though the light sensor solution would be very difficult to set up in a small space (requiring a sensor on the dial and light emitters at each potential position of the dial) and the camera solution would be prohibitively expensive.
Very small IC tilt/angular offset sensors do exist, but they rely on the changing position of the sensor in a static magnetic field, which means there are environments (again, the example of the switchable transformer, which creates a strong moving magnetic field in its general vicinity) which are too electronically noisy for the efficient use of such a device.